Ti Plasmid

 

Ti Plasmid

The Tumour inducing or Ti plasmid is present in the bacterium Agrobacterium tumifaciens.

It is widely used now as a cloning vector to deliver desirable genes to the host plant to get transgenic plants. The main characteristics of Ti plasmid are:

  • Size of the plasmid is ~ 250kbp
  • There are different kinds of Ti plasmids based on the different genes they possess, which code for different opines, e.g. leucinopine, nopaline, octopine, etc.
  • It is a pathogenic species to many dicotyledonous plants. It causes crown gall disease in plants.
  • It contains one or more T-DNA region
  • Agrobacterium tumifaciens has an ability to transform the normal cells to tumour cells by inserting a DNA piece known as T DNA and it starts producing chemicals, that are required by the bacterium
  • After inserting the desired gene into Ti plasmid, it loses its pathogenic ability but is still able to insert the desired gene into the plant cell
  • It contains vir or virulence genes, which transfer T-DNA region to plant cells and gets integrated into the plant genome
  • Ti plasmid can be modified as per the requirement to insert the desired genes
  • Agrobacterium tumifaciens is called “nature’s genetic engineer”

Ti Plasmid

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